/**
 * Copyright (C) 2010-2016 eBusiness Information, Excilys Group
 * Copyright (C) 2016-2020 the AndroidAnnotations project
 * <p>
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * Unless required by applicable law or agreed To in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package org.ohosannotations.internal.generation;

import com.helger.jcodemodel.writer.PrologCodeWriter;

import org.ohosannotations.Option;
import org.ohosannotations.internal.process.ModelProcessor;
import org.ohosannotations.logger.Logger;
import org.ohosannotations.logger.LoggerFactory;

import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.charset.UnsupportedCharsetException;

import javax.annotation.processing.Filer;

/**
 * 代码模型生成器
 *
 * @author dev
 * @since 2021-07-22
 */
public class CodeModelGenerator {
    /**
     * 选择编码
     */
    public static final Option OPTION_ENCODING = new Option("encoding", "UTF-8");
    private static final Logger LOGGER = LoggerFactory.getLogger(CodeModelGenerator.class);
    private final Filer filer;
    private final String header;
    private final String encoding;

    /**
     * 代码模型生成器
     *
     * @param filer 精密过滤器
     * @param aaVersion aa版
     * @param encoding 编码
     */
    public CodeModelGenerator(Filer filer, String aaVersion, String encoding) {
        this.filer = filer;
        this.header = "DO NOT EDIT THIS FILE." + System.lineSeparator()
            + "Generated using OhosAnnotations " + aaVersion + "." + System.lineSeparator() + System.lineSeparator()
            + "You can create an larger work that contains this file "
            + "and distribute that work under terms of your choice." + System.lineSeparator();
        this.encoding = encoding;
    }

    /**
     * 生成
     *
     * @param processResult 过程的结果
     * @throws IOException ioexception
     */
    public void generate(ModelProcessor.ProcessResult processResult) throws IOException {
        Charset charset = getCharset();

        SourceCodeWriter sourceCodeWriter = new SourceCodeWriter(filer, processResult.originatingElements, charset);

        PrologCodeWriter prologCodeWriter = new PrologCodeWriter(sourceCodeWriter, header);

        processResult.codeModel.build(prologCodeWriter, new ResourceCodeWriter(filer, charset));
    }

    /**
     * 得到字符集
     *
     * @return {@link Charset}
     */
    private Charset getCharset() {
        try {
            return Charset.forName(encoding);
        } catch (UnsupportedCharsetException exception) {
            Charset defaultCharset = Charset.defaultCharset();

            LOGGER.warn("The requested charset ({}) is not available, falling back to platform default ({}).",
                encoding + defaultCharset);

            return defaultCharset;
        }
    }
}
